1. Field of the Invention
This invention relates to 5,6,7,8-tetrafluoroanthraquinone derivatives and to a method for the manufacture thereof.
2. Description of Prior Art
Quinizarins and anthraquinonylamines are known as disperse dyes or pigments possessing high lightfastness and high heat-resisting property or as raw materials therefor. Their lightfastness and heat-resisting property, however, are still short of being fully satisfactory. Methods for the manufacture of these compounds have already been known to the art. For example, a quinizarin is synthesized by subjecting phthalic anhydride and a hydroquinone to Friedel-Crafts reaction. An anthraquinonylamine is synthesized by reducing a quinizarin into a leucoquinizarin with a reducing agent such as metallic tin, a tin compound, metallic zinc, or a reducing agent such as alkali metal thiosulfate and substituting the resultant leucoquinizarin for the hydroxyl group at the 1- or 4-position of an alkylamine or a phenylamine group.
Incidentally, fluorinated quinizarins or fluorinated anthraquinonylamines have never been known to the art. Methods for manufacture of such fluorianted products have never been known to the art.
An object of the present invention, therefore, is to provide 5,6,7,8-tetrafluoroanthraquinone derivatives, which are novel compounds, and a method for the manufacture thereof.
Another object of this invention is to provide 5,6,7,8-tetrafluoroanthraquinone derivatives, which serve as disperse dyes or pigments of very high lightfastness and heat-resisting property and as raw materials therefor and a method for the manufacture thereof.